- Free to Read
- Access by Xinjiang University
Violation of Bell's Inequality under Strict Einstein Locality Conditions
Phys. Rev. Lett. 81, 5039 – Published 7 December, 1998
DOI: https://doi.org/10.1103/PhysRevLett.81.5039
Abstract
We observe strong violation of Bell's inequality in an Einstein-Podolsky-Rosen-type experiment with independent observers. Our experiment definitely implements the ideas behind the well-known work by Aspect et al. We for the first time fully enforce the condition of locality, a central assumption in the derivation of Bell's theorem. The necessary spacelike separation of the observations is achieved by sufficient physical distance between the measurement stations, by ultrafast and random setting of the analyzers, and by completely independent data registration.
References (18)
- A. Einstein, B. Podolsky, and N. Rosen, Phys. Rev. 47, 777 (1935).
- J. S. Bell, Physics (Long Island City, N.Y.) 1, 195 (1965).
- S. J. Freedman and J. F. Clauser, Phys. Rev. Lett. 28, 938 (1972).
- A. Aspect, J. Dalibard, and G. Roger, Phys. Rev. Lett. 49, 1804 (1982).
- P. G. Kwiat, K. Mattle, H. Weinfurter, A. Zeilinger, A. V. Sergienko, and Y. Shih, Phys. Rev. Lett. 75, 4337 (1995).
- P. Pearle, Phys Rev. D 2, 1418 (1970).
- The observation that the photons in a pair, as used by us, are always found to have different polarization can not as easily be understood as the fact that the socks in a pair, as worn by Bertlmann, are always found to have different colors. J. S. Bell, J. Phys. (Paris), Colloq., Suppl. 3, C2, 41 (1981), reprinted in Speakable and Unspeakable in Quantum Mechanics (Cambridge University Press, Cambridge, 1987), pp. 139–158.
- A. Zeilinger, Phys. Lett. 118A, 1 (1986).
- G. Weihs, H. Weinfurter, and A. Zeilinger, in Experimental Metaphysics, R. S. Cohen et al. (Kluwer Academic Publishers, Dordrecht, 1997), pp. 271–280; Acta Phys. Slovaca 47, 337 (1997).
- P. V. Christiansen, Phys. Today 38, No. 11, 11 (1985).
- W. Tittel, J. Brendel, B. Gisin, T. Herzog, H. Zbinden, and N. Gisin, Phys. Rev. A 57, 3229 (1998).
- P. R. Tapster, J. G. Rarity, and P. C. M. Owens, Phys. Rev. Lett. 73, 1923 (1994); C. H. Monken, P. H. Souto Ribeiro, and S. Pádua, Phys. Rev. A 57, R2267 (1998).
- Precisely speaking, the modulator introduces a phase shift between the linearly polarized components parallel and perpendicular to its optic axis (at ). Together with two quarter-wave plates (at or ) before and after the modulator this results in a polarization rotation in real space as usually seen in circularly birefringent media. The latter quarter-wave plate can be abandoned here because it is parallel to the axis of the subsequent polarizer and thus introduces only a phase which cannot be measured anyway. The quarter-wave plate in front of the modulator is substituted by our fiber and the initial polarization controllers.
- U. Achleitner, master thesis, University of Innsbruck, Innsbruck, 1997.
- We tested our random number generator for exponential distribution of the occurring time intervals, for maximum entropy, and for short autocorrelation length. Further, we applied special tests normally used to judge the quality of pseudo-random-number generators. These results will be the subject of a future publication.
- J. F. Clauser, M. A. Horne, A. Shimony, and R. A. Holt, Phys. Rev. Lett. 23, 880 (1969).
- Original sets of data are available at our web site: http://www.quantum.at. We would appreciate receiving suggestions for possible variations of the experiment.
- N. D. Mermin, Phys. Today 38, No. 4, 38 (1985).